Like most great ideas, the goTenna was born out of necessity. In 2012, Hurricane Sandy downed cell towers in New York City and left the residents of an otherwise well-connected city vulnerable. Daniela Perdomo, an entrepreneur in the tech startup world at the time, saw the need for personal emergency communication systems, something that would bring traditional walkie-talkies to the 21st century. A few prototypes later, she produced the goTenna, a hand-sized, 2-ounce device with a retractable antenna that allows users to send and receive text and GPS information with their smartphones without cell service.

Perdomo’s design capitalizes on the omnipresence of the smartphone. Instead of carrying a separate walkie talkie, which Perdomo critiques as “allowing you to hear everyone else talking”, Perdomo wanted to make use of the Bluetooth Low Energy network already available to iPhone and Android devices. The process is simple: smartphones communicate a message to the goTenna through an in-phone app; the goTenna then transmits the message using long-range radio waves (151-154 MHz); surrounding goTennas, purportedly in the range of about 0.5-1 miles in the city to 4-6 miles across a desert, will then receive the radio waves with their retractable antennae; goTennas receiving a message will transmit the information to their paired Bluetooth devices; finally, the in-phone app displays the text message and/or location of the sender. And that’s it: friends located, help received.

But this success also highlights a limitation of the technology. To be useful, the goTenna and smartphone need to have battery power, an obvious problem for battery-guzzling smartphones. Fortunately, the goTenna’s ingenious design means smartphones can be kept in airplane mode and still send and receive messages. So instead of continually searching for service at a music festival, a trailhead or after a disaster, your phone conserves battery life — and this functionality will mitigate your phone bill when roaming in a foreign country. The goTenna also utilizes its home phone’s GPS for what is arguably its best feature: users can share their GPS location and view others on a detailed, preloaded offline map, all for free. No more blue dots sitting on a field of unbuffered white.

The goTenna’s decentralized, encrypted and completely offline communications appealing for any dealings that users want to keep secret.

Besides allowing users to conserve battery and communicate without service, the goTenna also serves as an emergency help button. Urgent messages fall into two categories: Shout and Emergency Chat. Shouting sends a message to every goTenna within range. Think of this as backcountry Tindering, or asking a neighbor to borrow fire-starter. Users can choose to opt out of being a Shout recipient, but no one can opt out of receiving an Emergency Chat. On an honor system, these messages are reserved for life-threatening situations.

The device comes along at just the right time for very different groups of people. Recent threats to privacy from tech companies, hackers and the government alike make the goTenna’s decentralized, encrypted and completely offline communications appealing for any dealings that users want to keep secret. This is no accident; by goTenna’s own admission, “We set out to build a consumer-ready, completely decentralized, end-to-end innocent or nefarious communication technology, without a ‘back-door’ for anyone, because it didn’t exist yet, and we thought it should. We’ll leave it at that.” Whether you’re just using yours for hiking or you’d rather not say what you’re using it for, the goTenna is a device that pushes the possibilities of communication in an entirely new direction, and one of the year’s most potent tools.